Remove drop shadows

- from all clips

![screen shot 2013-10-09 at 13 37 46](https://f.cloud.github.com/assets/109850/1297330/ad5fcf9c-30df-11e3-8356-e7739dfb9d0e.png)

- left navigation

![screen shot 2013-10-09 at 13 37 27](https://f.cloud.github.com/assets/109850/1297332/b361de6c-30df-11e3-8506-cf1da6dad3ab.png)

- thumbnails

![screen shot 2013-10-09 at 13 37 16](https://f.cloud.github.com/assets/109850/1297333/b7a8bcb6-30df-11e3-875b-3ec85697e1ac.png)